ML20011A470
| ML20011A470 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 10/31/1981 |
| From: | Varela A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20011A456 | List:
|
| References | |
| ISSUANCES-OL, NUDOCS 8110130450 | |
| Download: ML20011A470 (4) | |
Text
4 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of
)
)
UNION ELECT'lIC COMPANY
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Docket Nos. 50-483 OL
)
(Callaway Plant, Unit 1)
)
AFFIDAVIT OF ANTHONY A. VARELA IN SUPPORT OF NRC STAFF MOTION FOR
SUMMARY
DISPOSITION ON THE ISSUE OF JOINT INTERVEN0RS'S CONTENTION I-B(1)_
I, Anthony A. Varela, being duly sworn, depose and state:
1.
I am a civil engineer with the U.S. Nuclear Regulatory Commission.
Since February 1979, I have been assigned to the Region I Office of Inspection and Enforcement. During 1977, I was assigned to inspec+ the Callaway facility in Region III.
2.
I cor ducted four inspections of the Callaway Plant in 1977. My responsibilities during those investigations consisted of:
(1) ascer-taining whether adequate quality assurance plans, instructicns, and
(
procedures had been established for the construction of concrete l
structures; (2) providing an independent evaluation of the performance, l
work in progress, and completed work to ascertain whether activities relative to concrete construciton were accomplished in accordance with NRC recuirements; and (3) reviewing the quality related records to ascertain whether these records reflected work accomplished ennsistent with NRC requirements and license commitments. The results of these inspections are contained in the following NRC inspection reports:
l l
8110130450 011007 PDR ADOCK 05000483 C
pyn L
50-483/77-01, conducted January 12-14, 1977.
50-483/77-03, conducted April 4-9, 19/7.
50 483/77-06, conducted June 28 - July 1,1977.
50-483/77-07, conducted August 30 - September 2, 1977.
3.
I was present for part of the pouring of the concrete for the section of the reactor meat area in which the crack identified in Joint Intervenors' Contention I-B(1) was found. The pour, which took place in early April of 1977, lasted approximately sixty-two hours.
During that period, e'ther I or another Staff inspector was present at the placement at all times.
The results of our inspection are documented in NRC Report 50-483/77-03. We found no substantive inadequacies with the pour.
4.
Union Electric reported by telephone to Region III on May 10, 1977, a pot: 1tial significant deficiency under 10 C.F.R. 9 50.55(e). A aCk hdd been discovered on the top surface of the reactor base mat concrete avjacent to a wide-flange steel member which had been embedded in the concrete to serve as an enchor for floor liner plate.
Following welding of the liner plate on one side of the embedded steel member, a crack cpproximately k inch wide was discovered on the opposite side of the member. Applicant immediately initiated an investigation into the cause of the crack.
5.
The embedded steel member is located at the top of the base mat surrounding the reactor vessel moat.
It is approximately 65 feet long and continues circumferentially 270 degrees around the moat. The concrete cr ick was discovered outside of the embedded member the day following completion of the welding of the liner plate to the embedded member.
E 4,
6.
The crack was cause by the heat genersi.ed from continuous welding without any interruption or stagger in the weld sequence.
Post-weld contraction of the liner attached to the embedded member pulled the member inward, causing the concrete to crack on the outside of the member.
Quality control inspectors and field engineers reported the above deficiency in construction in Nonconformance Report NCR 2-0631-C-A, datai May 10, 1977.
7.
The recommended disposition consisted of the complete removal of the crack and replacement of the removed concrete. The replacement concrete was incorporated in a subsequent concrete pour that would have taken place without regard to the occurrence of the crack.
This pour took place on June 2,1977; quality control documentation of the pour is identified in NRC Report 50-483/77-06.
8.
The significance of the crack was evaluated by Union Electric and its architect-engineer (Bechtel).
They determined that the crack was not a significant deficiency pursuant to 10 C.F.R. 6 50.55(e) in that it would not have adversely affected the safety of the plant even if it had not been corrected.
I agree with this assessment.
9.
The cause of the crack was not due to a deficiency in the concrete-related procedures followed at the site. A welding contractor prosecuted his work in a way that resulted in the crack. Despite the attention to individual control by different contractors of separate sequential features of nuclear construction, lack of interface between the contractors can sometimes cause problems.
Corrective actions were taken by Union Electric and the welding contractor to prevent subsequent
4 weld-related cracks in concrete. Documents identifying the corrective actions are listed in NRC Report 77-06.
10.
I did not physically inspect the repair of the removed crack.
I did, however, visually observe the replacement concrete to be sound.
I also reviewed quality control dornmentation of the pour and interviewed the l
responsible quality control personnel.
I found no indication of any deficiencies in the pour and see no reason to believe the repair was inadequate in any.way.
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%>thonyA. Var,unm L a
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Subscribed and sworn to before me this day of October, 1981.
Sont Q A[Um Notary Fublit
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SARAH A.DILISSIO, Notary Public Upper Wrlon Twp., Montgomery Co.
My Commission expire;: My comrnission apires oec. s,1983 g.
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